Tarnish prevention of silverware



Patented 1946 umrao Ys'rA rEs PATENT OFFICE TARNISH PREVENTION OF SILVERWAR John B. Rust, West Orange, N. 3., assignor to Montclair Research Corporation, a corporation of New, Jersey No Drawing. Application April 7,1944, SerialNo. 530.063

Claims.

This invention relates to a-method of retarding the tarnishing of silver, with particular reference to retarding the surface staining of silverware.

The ready tendency for surfaces of silver to rn h and stain on exposure to ordinary atmospheric condition presents a constant cleaning problem which is annoying and labor-consuming. A solution of this problem would be of definite benefit not only to stores having silverware on exhibit but also to households where such silverware as candlesticks, bonbon dishes, trays, etc., are usually left exposed on tables, Sideboards, etc, and consequently need frequent cleaning. It has been suggested to protect silverware by applying a thin coatingof'collodion. It has also been suggested to protect silverware by confining it in a restricted space exposed to the vapors. of a volatile amine. While this might be accomplished under certain conditions in a store, it would be impractical in a home.

silverware, allowing the film to dry and giving it Q then a slight bufling. After application and buffing the silverware has a bright'appearanceand remains bright even after a month's exposure to I have now found a practical solution for substantially retarding the formation of tarnish films and stain'on the surfaces of silverware without any necessity whatsoever-of confining the silverware to a restricted space. a

It is known that the higher'aliphatic amines such as stearyl amine which are waterinsoluble become water-soluble when the corresponding lower aliphatic acid salt is formed, such as stearyl amine acetate.

I have now found that water-soluble salts of the higher aliphatic amines exert an excellent protective action on silverware.

In practising the invention it i merely necessary to coat the silverware with a dilute solution of a water-soluble salt of a higher aliphatic amine. A satisfactory method of accomplishing the above is to make a 1% to 5% (preferably a 2%) solution in water, impregnate with this solution a wad of cotton, then rub this wad lightly over clean silverware, making certain that a film is left on every part of the surface which is to be protected. The film is then allowed to dry and given a slight buffing. The solution can also be applied by dipping or spraying. Silverware so treated will remain untarnished for periods over a month when left in ordinary atmospheric conditions while an untreated piece will be badly stained and tarnished when left under similar conditions.

amine, palm-ityl amine, stearyl amine, oleyl amine nishing'which'comprises depositing on the surordinary atmospheric conditions.

Example 2.A 2% solution of palmitylamine acetate is applied to clean silverwar surface as in Example 1. The surface remains tarnish-free.

Example 3.-Lauryl amine acetate in 2% aqueous solution applied to silverware as in Example- 1 gives a surface which is still bright after a I month when exposed to atmospheric conditionsnormally conducive to tarnishing.-

I claim: A 1. A process for protecting silverware from tarface thereof a thin continuous film of 'a fatty acid salt of a primary aliphatic amine, the fatty acid containing from 1 to 4' carbon atoms and the primary amine from 12 to 22.

2. A process for protecting silverware from tarnishing which comprises applying to the surface thereof a dilute aqueous solution of afatty acid salt of a primary aliphatic amine, the fatty acid and other primary amines of from '12 to about 22 carbon atoms. As fatty acid I can use formic,

containing from 1 to 4 carbon atoms and the primary amine from 12 to 22, removingthe water therefrom, and buffing the surface;

3. A process for protecting silverware from tarnishing which comprises depositing on the surface a thin continuous film of stearylamine acetate.

4. A process nishing which comprises depositing on the surface a thin continuous film of palmitylamine acetate.

tate. v

JOHN B. RUST.

scope and spirit for protecting silverware from tar- 

